/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Firefox Home.
 *
 * The Initial Developer of the Original Code is the Mozilla Foundation.
 *
 * Portions created by the Initial Developer are Copyright (C) 2010
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 *  Stefan Arentz <stefan@arentz.ca>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#import "NSData+AES.h"

@implementation NSData (AES)

/**
 * Return an AES256/CBC/PKCS7 encrypted version of the data. Returns nil if the encryption failed.
 */

+ (id) ciphertextDataByAES256EncrypingPlaintextData: (NSData*) plaintextData key: (NSData*) key iv: (NSData*) iv padding: (BOOL) padding
{
	NSData* result = nil;
	
	size_t bufferSize = [plaintextData length] + [key length];

	void *buffer = calloc(bufferSize, sizeof(uint8_t));
	if (buffer != nil)
	{
		size_t dataOutMoved = 0;

		CCCryptorStatus cryptStatus = CCCrypt(
			kCCEncrypt,
			kCCAlgorithmAES128,
			padding ? kCCOptionPKCS7Padding : 0,
			[key bytes],
			kCCKeySizeAES256,
			[iv bytes],
			[plaintextData bytes],
			[plaintextData length],
			buffer,
			bufferSize,
			&dataOutMoved
		);
		
		if (cryptStatus == kCCSuccess) {
			result = [self dataWithBytesNoCopy: buffer length: dataOutMoved freeWhenDone: YES];
		} else {
			free(buffer);
		}
	}
	
	return result;
}

+ (id) plaintextDataByAES256DecryptingCiphertextData: (NSData*) ciphertextData key: (NSData*) key iv: (NSData*) iv padding: (BOOL) padding
{
	NSData* result = nil;

	size_t bufferSize = [ciphertextData length];

	void *buffer = calloc(bufferSize, sizeof(uint8_t));
	if (buffer != nil)
	{
		size_t dataOutMoved = 0;

		CCCryptorStatus cryptStatus = CCCrypt(
			kCCDecrypt,
			kCCAlgorithmAES128,
			padding ? kCCOptionPKCS7Padding : 0,
			[key bytes],
			kCCKeySizeAES256,
			[iv bytes],
			[ciphertextData bytes],
			[ciphertextData length],
			buffer,
			bufferSize,
			&dataOutMoved
		);
		
		if (cryptStatus == kCCSuccess) {
			result = [self dataWithBytesNoCopy: buffer length: dataOutMoved freeWhenDone: YES];
		} else {
			free(buffer);
		}
	}
	
	return result;
}

@end